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Statistic | Type of school1 | Block R1 | Block R2 | Block R3 | Block R4 | Block R5 | Block R6 | Block R7 | Block R8 | Block R9 | Block R10 | Block R11 | Block R12 | Block R13 |
---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
Number of scaled items | † | 10 | 10 | 10 | 10 | 9 | 10 | 11 | 10 | 9 | 10 | 11 | 11 | 11 |
Unweighted sample size | Public | 2,200 | 2,200 | 2,100 | 2,200 | 2,200 | 2,200 | 2,200 | 2,200 | 2,200 | 2,200 | 2,200 | 2,300 | 2,200 |
Nonpublic | 200 | 200 | 300 | 200 | 200 | 200 | 200 | 200 | 200 | 200 | 200 | 200 | 200 | |
Weighted average item score2 | Public | .71 | .72 | .71 | .59 | .56 | .59 | .63 | .63 | .57 | .59 | .56 | .67 | .56 |
Nonpublic | .77 | .79 | .78 | .70 | .67 | .68 | .72 | .71 | .66 | .72 | .68 | .74 | .66 | |
Weighted average polyserial | Public | .70 | .71 | .70 | .68 | .73 | .65 | .71 | .75 | .69 | .67 | .71 | .72 | .66 |
Nonpublic | .69 | .70 | .74 | .77 | .77 | .71 | .74 | .85 | .75 | .70 | .75 | .76 | .66 | |
Weighted alpha reliability | Public | .73 | .74 | .70 | .74 | .74 | .69 | .76 | .78 | .75 | .74 | .80 | .78 | .72 |
Nonpublic | .71 | .66 | .69 | .79 | .73 | .72 | .75 | .82 | .77 | .70 | .80 | .76 | .67 | |
Weighted proportion of students attempting last item 3 | Public | .90 | .94 | .99 | .84 | .96 | .98 | .97 | .87 | .94 | .92 | .98 | .96 | .88 |
Nonpublic | .94 | .98 | .99 | .92 | .96 | .99 | .98 | .93 | .97 | .96 | .96 | .97 | .97 | |
† Not applicable. 1 Nonpublic school sample includes only private schools, including Catholic schools. BIE and DoDEA schools are not included in either the public or nonpublic category. 2 The "Weighted average item score" of polytomous items is standardized to have a scale of 0 to 1 so they are comparable to dichotomously scored items. 3 The "Weighted proportion of students attempting last item" is equal to 1 – (Percent not responding to last item / 100). NOTE: Item statistics in this table are described on the page Blocks of Items. SOURCE: U.S. Department of Education, Institute of Education Sciences, National Center for Education Statistics, National Assessment of Educational Progress (NAEP), 2015 Reading Assessment. |